Go to the wiki and search for the words 'certificates cli' and you'll find a Certified Document that tells you how to generate the certificates for each version of Zimbra, pick the one that's suitable for your versions.

Your hosts file is incorrect as, apparently, are your DNS records. According to the output of the commands you've posted there's no MX record for your server. I'd suggest you go to the Split DNS article and read what's necessary for the correct configuration of the hosts & resolv.conf files adn the DNS A & MX records. When you've read that article and fixed your config you can run all the commands in the 'Verify....' section of that article to confirm your settings.

I'm assuming this is a single server install? If that's the case then you should not have imapproxy nor memcached installed or running, search the forums for details on how to disable and remove those services and reset the ports to their defaults.

But, my zimbra settings was working, and my server was working correctly

Since my I restarted my dedicated server I have those problems of configuration, but I don't changed nothing (at less since some month, but the dedicated was running without restart since two months).

I use the default hostname, the one used by my dedicated hoster.

I will check all thoses informations, but there'snt any way to fix my problem and start the mail server before having corrected all those things ?

About those things, how I can't change nothing about mx record for exemple since I use a subdomain name ?
There is a way to keep my hostname and to correctly set mx records to pass the dig request side ?